Real time PRF control system for SAR

This paper presents a real time solution to link the pulse repetition frequency of a synthetic aperture radar to the aircraft forward velocity without using an inertial navigation system. This allows the SAR-system under consideration to operate with a constant spatial PRF. The aircraft forward velocity is extracted using the reflectivity displacement method from the radar backscatter signal azimuth spectra. The control system used for coupling the RDM with the variable PRF unit is a nonlinear and adaptive one, based on an ideal on-off relay